Treasury Secretary Timothy Geithner, left, with former FDIC Chair Sheila Bair on Oct. 1, 2010, in Washington. (Pablo Martinez Monsivais/AP)

The Obama and Bush admin­istrations largely ignored the needs of beleaguered homeowners while focusing too narrowly on the well-being of Wall Street during the worst financial crisis since the Great Depression, according to a new book by a top participant in the government’s response.

The book, “Bull by the Horns,” by former Federal Deposit Insurance Corp. chairman Sheila Bair, says both administrations’ top advisers paid little more than lip service to helping borrowers at risk of foreclosure, instituting programs they knew were likely to fail and ignoring her recommendations about how to improve them.

By contrast, she said, senior advisers were willing to go to great lengths to rescue the nation’s top banks — without demanding accountability from top financial executives.

A Republican who became a champion among liberals for her firm stance toward Wall Street and noisy presence in favor of homeowner assistance, Bair reserved her sharpest words for Treasury Secretary Timothy F. Geithner, who served as president of the Federal Reserve Bank of New York in the lead-up to the financial crisis.

After she recommended that President Obama name former Federal Reserve chairman Paul Volcker as Treasury secretary, she wrote, Obama’s decision to tap Geithner was “a punch in the gut.” She considered Geithner the “bailouter in chief” because he wanted to make unconditional guarantees to top banks to keep them afloat without demanding much in return.

In particular, amid discussions about how to save Citigroup, she wrote, “Tim seemed to view his job as protecting Citigroup from me, when he should have been worried about protecting the taxpayers from Citi.”

The acrimony between Geithner and Bair has been well documented in Washington. Geithner’s defenders note that the policies he supported helped prevent a catastrophic collapse of the financial system and have turned out less costly than initially projected. And as evidence that he did not show favoritism toward Citi, they note that in 2004, the New York Fed levied a $70 million fine against the firm for improper subprime lending practices.

“Every decision was looked at through the prism of ‘What is going to help the Main Street economy?’ Economies cannot grow without a functioning financial system,” Lee Sachs, a former top aide to Geithner, said in an interview. “And the steps that two administrations took were viewed through that lens. It had nothing to do with helping those fine fellows on Wall Street.”

Sachs said Bair and Geithner tried to do what was best for the economy, even though their philosophies often differed. “All the options were tremendously distasteful for everyone,” he said. “That doesn’t mean you didn’t have to pick a course of action.”

In a separate interview Tuesday, Bair agreed that Geithner and other government officials had good intentions but said those intentions did not always lead them to wise decisions. “I don’t pull punches. I did take people to task. But I didn’t do so unless there was a good reason to do so,” she said, adding: “The policies were all focused on making banks profitable again.”

Asked at an event Tuesday in New York whether he planned to write his own book, Geithner said he’s “not really the type to sit alone at a desk and write.” He added with a laugh: “A lot of people are telling my story.”

Bair wrote that the George W. Bush administration showed little interest in any significant effort to help at-risk borrowers and that Obama’s team, which had promised to do better, also proved disappointing. She said Geithner and Lawrence H. Summers, Obama’s former National Economic Council director, created the Home Affordable Modification Program, Obama’s main plan to aid homeowners, more for splash than substance.

“HAMP was a program designed to look good in a press release, not to fix the housing market,” she wrote. “Larry and Tim didn’t seem to care about the political beating the president took on the hundreds of billions of dollars thrown at the big-bank bailouts and AIG bonuses, but when it came to home owners, it was a very different story. I don’t think helping home owners was ever a priority for them.”

Bair also didn’t mince words about how she viewed the top bankers at the massive Wall Street firms that helped wreck the economy by placing enormous bets on risky mortgage-backed securities.

“I doubted that he was up to the job,” she wrote of Vikram Pandit, who had been tapped to clean up the troubles inside Citigroup. The bank noted in a statement that it had returned to profitability under his watch as a smaller, safer firm.

Bair said Ken Lewis, head of Charlotte-based Bank of America, was seen as “somewhat of a country bumpkin” by the New York executives, “and not completely without justification.”

“He was a decent traditional banker, but as a deal maker, his skills were clearly wanting,” she wrote, citing his ill-fated acquisition of subprime mortgage lender Countrywide Financial.

Wells Fargo Chairman Richard Kovacevich “could be rude and abrupt, but he and his bank were very good at managing their business and executing on deals.” Goldman Sachs chief executive Lloyd Blankfein‘s “puckish charm and quick wit belied a reputation for tough, if not ruthless, business acumen.”

By contrast, Bair praised JPMorgan Chase’s Jamie Dimon as the smartest of the big bankers. “Dimon was a towering figure in height as well as leadership ability,” she wrote, citing his foresight in recognizing the coming financial storm in 2006 and taking measures to protect his bank.

Bair also recounted the lengthy battle over new legislation to overhaul the nation’s patchwork financial regulatory system, during which she supported the idea of a new consumer watchdog agency and pressed for powers to allow the government to seize and wind down large, troubled financial firms.

She suggested abolishing the Office of the Comptroller of the Currency, saying it “failed miserably” in its regulation of national banks. She expressed disappointment in the $25 billion government settlement with banks over their flawed and fraudulent foreclosure practices, arguing that it will help only “on the margin.”

Toward the end of her book, Bair lamented that lawmakers and regulators didn’t do more in the years before the crisis to safeguard the country’s financial system. In addition, she wrote, financial executives failed to run their businesses responsibly.

But she said in the interview that the missteps and missed opportunities didn’t end there. Even after the crisis hit, she said, officials in charge of fixing the mess took too many wrong turns.

“I thought that over time I would be more dispassionate,” she said Tuesday about the writing process. “I just got angry all over again when I was reliving it. We could have done a lot of things differently. We could have done a lot of things better.”